Embarassing, but I don't really know how to tell if the strings I have are going bad. I have a set of Helicore Orchestra mediums that have been on for slightly over a year, played about four-five hours a week on average (all arco). The strings don't really seem much different than when first played in -- no visible signs of wear. However, the A seems to wobble on its pitch a bit, which I don't remember it doing before (and that could be my finicky electronic pitch sensor rather than the string). Also, the G sounds a bit tinnier to me than it used to, but again, that could be 'cause the bridge was bumped... What are the symptoms I should expect that would tell me it's time to buy a new set, or is it a "You'll know it when you hear it" deal?